Greenland really was green, world's oldest DNA reveals

THE oldest DNA found on earth has been collected from under a
kilometre of ice in Greenland, revealing that the frozen island
really was once green.

Half a million years ago Greenland was covered by lush forests
filled with butterflies, moths and the ancestors of beetles, flies
and spiders. The finding has implications for global warming,
suggesting the Greenland ice sheet, which holds enough water to
raise sea levels by seven metres, might not melt as quickly as
thought.

A Danish-led team, including the Australian researcher Michael
Bunce, extracted the ancient DNA from the muddy bottoms of cores
drilled deep into the ice cap in southern Greenland. The
researchers identified genetic traces of a surprising variety of
tree species, including spruce, pine and yew. The team believes the
DNA is between 450,000 and 800,000 years old, based on their
analysis of insect genetic material.

Dr Bunce, of Murdoch University, said it was a fascinating new
way to study the past. "Preserved DNA from plants, animals, insects
and bacteria that died hundreds of thousands of years ago can aid
in our understanding of how the earth's environment has changed,"
he said.

Researcher Eske Willerslev said: "We have shown for the first
time that southern Greenland, which is currently hidden under more
than two kilometres of ice, was once very different to the
Greenland [of] today."

The discovery of ancient DNA from a warm period half a million
years ago suggests that ice on top of the ancient forest did not
melt as believed during the last warm period, 116,000 to 130,000
years ago, when temperatures were 5 degrees higher than today. If
it had, the remains of the ancient trees and insects would have
been replaced by new flora and fauna.

"If our data is correct, this means that the southern Greenland
ice cap is more stable than previously thought," said Professor
Willerslev, whose team's findings are published today in the
journal Science.

This did not mean sea levels would rise more slowly than
predicted, he warned. The five- to six-metre rises during the last
warm period must have come from sources other than Greenland, such
as Antarctica, he said. "As the earth warms from man-made climate
change, these sources would still contribute to a rise in sea
levels."

Erik the Red, who settled in Greenland 1000 years ago, named it
to lure more settlers, although a small area not covered by ice
would then have been very green.